I’m about to put down this epoxy coating in my garage, and looking online for other people’s experience, I see that some have filled the gaps between the slabs with some kind of sealant before the coating, so the floor is completely smooth. The end result looks great, but are the gaps merely the result of the pouring process, or do they provide for expansion and contraction with changing temps? And if the latter, would sealing and covering them lead to problems down the line?
If it’s okay to fill them, what kind of sealant should I use? (I plan to ask Rust-Oleum, but the help line isn’t open on weekends. :rolleyes:)
Sometimes the lines are cut in after the fact (like on a patio or large slab that’s done in one pour). In these cases, and many others, it’s so that when the concrete cracks, it cracks (hopefully) along those lines as opposed to taking some random, unsightly path.
As for filling them, I don’t see why you couldn’t, but won’t the epoxy just fill them in?
They form fault line; break here if you must break.
my point was that, if the structural (for the slab, obviously) purpose9s) are active, expect the line to reform. the epoxy will not hold the forces involved.
If the appearance of the epoxy surface is paramount, the re-appearance of the joint would be tolerable. if the idea is to create a showroom quality surface, the epoxy is not apt to work.
That’s what I was afraid of. The house is about 20 years old, so perhaps it has settled and expanded/contracted as much as it’s going to. There are little hairline cracks at the bottom of most of the seams, so they’ve done that job. There’s another very thin but long crack in the middle of one slab that appeared, much to our surprise, after a minor earthquake several hundred miles away, a year or two ago. I will probably fill that in with concrete patch.
No. The seams are about one inch thick and about 3/4 inch deep. The epoxy is just a very thick paint. I think if I were to pour it into the gap, some of it might ooze through the cracks I mentioned, and who knows how much it would take, or how long it would take to dry?
Are you responding to Joey P’s post above? If not, I don’t think I understand what you’re saying.
At the bottom of the Amazon page for the product, the second customer review (as of the date of this post), titled “Awesome product!”, shows before and after pictures of a floor with a single longitudinal seam filled in.
If you go here, and look at the pictures of the review titled “Good but not perfect,” you’ll see someone who left the seams in.
I think the floor with the filled seams looks much nicer.
My thinking (and hope) is that a flexible plastic sealant, topped with epoxy, could withstand the microscopic movements and shifts of the slabs without cracking or otherwise becoming noticeable.
I put that same epoxy on my garage floor. Said floor was, at a guess 50 years or so old, and had a large crack running all the way across it. It also had significant spalling, mostly around the locations where the rear wheels of a vehicle parked in it sat and dripped melted snow to destroy the concrete with freeze/thaw expansion cycles. I chipped out all the loose bits around where the spalling was and patched using a bonded topping concrete mix. I filled the large crack (1/4" to 3/8" wide) using Rustoleum’s epoxy concrete patch. It’s made it through two Saskatchewan winters without re-cracking so far. It’s not a cheap product, however, and it takes more than you think. I’d be inclined to just leave a nice straight joint cut open.
The epoxy paint itself won’t fill even very small cracks.
I also recommend getting the grit compound they sell to make it non-slip, as the finish is extremely slick and glossy, to the point of being perilous when wet or icy (although I do see your location is Nevada, so perhaps you can disregard this).
I’d imagine there would be no problem filling them with a silicone-based caulk - don’t let it protrude above the surface level, and don’t smear the sealant over the edges of the slabs (it will stop the epoxy adhering).
If there’s thermal expansion, the silicone will just squish. You might lose the epoxy off the top of the seam line, but that shouldn’t be a problem.
Like others have already told you, the slab may move a bit, and make lines appear, but you can simply pour plaster of paris in them, let it dry, sand smooth, and epoxy over it.
It will give you the look you want, wont harm the floor any, and the plaster dries hard unlike caulking and such.
Same thing is done a lot when you are putting tile on the slab, and do not want the tile indenting down into the expansion joints and breaking.